Railway traffic controlling apparatus



ug. 10, 1937. H, A, WALLACE 2,089,455

RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed July 17, 1934 3 Sheets-Sheet l RZHS' Ll V C Slow Pic/vago yepbepf '/1. Waage@ [722911 INVENTOR BY UU/IMM A TTORNE Y Aug. 10, 1937. H, A, WALLACE 2,089,455

RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed July 17, 1954 5 Sheets-Sheet 2 Si Si MZ BZ 49 60 Lm A 61 HZAR Fly. 2

INVENTOR HQI'bQPz .Wallace y BY ATTORNEY Aug. 10, 1937. H. A. WALLACE 2,089,455

' RAILWAY TRAFFIC CONTROLLING APPARATUS Driginal Filed July 17, 1934 3 Sheets-Sheet 3 IN VENT OR Hepbem Wallace BY @RW @u A TTORNEY Patented Aug. 10, 1937 UNHTED STATt PATENT @FFIQE RAILWAY TRAFFC CONTRQLLING APPARATUS Application July 17, 1934, Serial No. 735,572 Renewed October 24, 1936 18 Claims.

My invention relates to railway traflic controlling apparatus, and particularly to signaling apparatus for stretches of single track provided with passing sidings which apparatus is controlled in part from a remote point such as a dispatchers cnice. One feature of my invention is the provision of means for reversing the established direction of traffic in a single track stretch before a train moving in one direction leaves the stretch so that an opposing train can receive its signal and enter the single track stretch without loss of time as soon as the stretch becomes unoccupied.

I will describe four forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. la is a view showing a typical layout of track and signals, and includes a diagrammatic view of the line circuits for a stretch of track toI which my invention may be applied. Fig. 1b is a diagrammatic View showing the local circuits associated with signal Ei! of Fig. la. Fig. lc is a diagrammatic view showing the local circuits for signals R2, LA2 and LBR. Fig. 1d is a diagrammatic view showing the control circuits for back lock relays for signal R2 and for signals LA2 and LBZ. Fig. le is a view showing a portion of the local circuits associated with signal Il. Figs. 1f and 1g are diagrammatic views showing the lighting circuits for signals LA2 and LB2, respectively. Fig. 2a. is a view showing the same layout of track and signals as Fig. la but showing the line circuits as arrange-d to illustrate a modified form of my invention. Fig. 2b illustrates a modification of a portion of the circuits of Fig. lb employed with the modified form of my invention illustrated in Fig. 2a. Fig. 3 is a view showing the same layout of track and signals as Fig. la, but with the circuits arranged to show a third form of my invention. Fig. 4 is a view showing how my invention may be employed when staggered intermediate signals are used.

Similar reference characters refer to similar parts in each of the several views.

In order to simplify the drawings and to enable the circuits to be more readily traced, the track switch and each signal shown in the drawings has been identied by a number and each relay by a letter, or combination of letters, with a numerical prex identifying the switch or signal with which the relay is associated. The various relay contacts referred to herein are identified by number, and those contacts not adjacent the respective relays which operate them bear the reference characters for the respective relays as well as the numbers identifying the contacts.

Referring to Fig. la, the track diagram at the top illustrates a typical portion of a single track stretch of railroad having the opposing intermediate signals it? and II and opposing head block signals R2 and LA2 or LBZ. This stretch includes a switch section IT containing a track switch i and provided with the usual detector track circuit having a track relay ITR, and also includes a single track portion divided into a plurality of sections, of which only the sections 2T, IGT and part of I IT are shown, these sections being provided with the usual track circuits having track relays 2TH., IUTR and IITR, respectively. Traiic moving toward the right into this stretch of track is governed by the automatic signal i@ which is one of the usual intermediate block signals of an absolute permissive block signaling system, while trafc moving toward the left is governed by the head block signals LA2 and LB2 according as switch I is in its normal or reverse position. Signals LA2 and LB2 are controlled in part from a remote point such as a dispatchers office and are also controlled in part by the track relays of the stretch and by apparatus associated with the automatic signals Iii and I I. The opposing head block signal R2 governs traiiic moving toward the right out of section 2T, and the automatic signal II governs trailic moving toward the left out of section IT. Signal Ill is controlled by a slow pick up, slow release repeater relay IUI-IP shown in Fig. 1b, which relay is in turn controlled by a polarized line relay IBI-I,

while the opposing signal Ii is similarly controlled by a corresponding relay IIHP, shown in Fig. le, which is in turn controlled by aline relay I IH. In considering the circuits herein disclosed, it is to be understood that a local source of current is provided at each signal location, but for simplicity the circuits have been illustrated diagrammatically, and instead of showing the local sources and the wires leading thereto in detail 'only the terminals of the sources are shown, these being designated in each case by the reference characters B and C. Assuming that relay RAZI-I shown in Fig. 1c, for controlling arm A of signal R2 is energized, the circuit for relay ISH shown in Fig. 1a may be traced from terminal B of a suitable source of current, through pole-changer contact 2 operated by relay RAZH, back contact 3 of the manually controlled relay LZHS of Fig. 1c, back contact I of the line relay L2H for controlling signals LAZ and LB2, front contact 5 of relay LZGP of Fig. 1d, front contacts 6 and 'I of track relays ITR and 2TR, respectively, wire 8,

front contact 9 of track relay lDTR, relay I 0H,

front contact I2 of relay IUTR, wire I3, polechanger contact I4 of relay RAZH to terminal C 5 of the same source of current.

Relay LiGP, which has a contact 5 in the circuit just traced, is a back lock relay for signals LA2 and LBR having a circuit including back contacts of the signal relays LB2H and LAZH' l as shown in Fig. 1d, and relay LZGP is energized when signals LAZ and LB2 indicate stop. It follows', therefore, that the circuit for relay IIIH is open when a train occupies any part of the stretch between signals I0 and LA2, or when rel lays LZH or L2HS are energized, and that the polarity of current supplied to relay itl-l, is determined by the position of relay RA2I-I.

As indicated in Fig. 1c, relay RAZl-I is controlled by a line relay RZH which it is to be understood is controlled by conditions in the main line'stretch to the right of section IT, and by a manually controlled relay 'R21-IS, and becomes energized only when traino conditions are such as to permit signal REA to properly indicate caution or clear. Referring to Fig. 1b, `the circuit for relay tIlHP includes a front contact l5 of relay iIlH so that the slow pickup repeater relay lill-IP becomes energized at the end of its time period after relay lHis energized, and releases at the end of its release period after IDH releases. Re-

lay IDHP is the usual slow pickup slow release relay associated with an intermediate signal of an absolute permissive block signaling system, and together with the relay HBH, as is clear from Figs. la and 1b, controls the signal lamps G, Y and R of signal It in such a manner that lamp R will be lighted to cause signal Ill to display a stop indication when any portion of the stretch between signal it and the opposing signal L2A Ilo vor L2B is occupied, lamp Y will be lighted to cause the signal to indicate caution when the stretch is unoccupied and relay RAZH is deenergized, and lamp G will be lighted to cause the signal toindicate proceed when the stretch is unoccupied and relay RAEH is energized. Relay IElS in Fig. 1b is the usual directional stick relay associated with the intermediate signal Ill, and is provided with a pickup circuit which may be traced from terminal B, back contact I6 of an auxiliary relay mZ shown in Fig. la, back contact I'I-of track relay ISTR, front contact I8 of relay IGI-1P, relay IGS to terminal C, and which becomes closed when a train moving toward the rright passes signal IIJ at clearer caution, Re-

lay IUS is provided with a stick circuit which may be traced from terminal B, back contact I6 of relay IElZ, back contacts Il and I 8 of relays ISTR 'and IQHP in multiple, front contact i9 and winding of relay IIlS to terminal C, so that when relay I S once becomes energized it will remain picked up as long as relays lOl-IP and IIlZ remain deenergized. Relays I 0S and IOHP together control the energization and polarity of current supplied to the circuit comprising wires B and I3 for controlling the next signal in the rear ofA signal Il), not shown, for governing trafce moving toward the right toward signal Ill, by means of contacts 2i), 2l and 22. Relay IIS is the corresponding directional stick relay for signal I I and its circuits as shown in Fig. le, are similar to those for relay IlIS except that they do not include arcontact of an auxiliary relay such as relay I HZ, an auxiliary relay being not needed for the control of an intermediate section such as that governed by signal II, Relays IIS and I II-LP together control the energization and polarity of current supplied to the circuit for line relay L2H. V

Referring to Fig. la and assuming that relay II HP is energized, the circuit for the line relay LZ1-I for controlling signals LAE and LB2 is from terminal B, pole-changer contact 23 of relay I SHP, front contacts 24 and 25 of relays I KHP and I IS in multiple, back contacts 26 and 21 of relays IQHP and I US, respectively, front contact 28 of track relay ITR, wire 29, back contacts 3Q and 3l of the manually controlled relays LEI-ISP and LQHS, front contact 32 of relay ZTR, relay L2H, front contact 33 of track relay 2TR, wire I3, front contact I2 of relay IUTR, pole-changer contact Si of relay lll-IP to terminal C of the same source of energy, so that relay LZI-l is energized when the portion of the stretch between signals Iii and R2 is unoccupied and relays IBI-IP and IUS are deenergized, provided either the section to the left of signal II is occupied by a train moving toward the left so that relay I iS is energized or provided that section is unoccupied and relay IIHP is energized.

Referring to Fig. lc, the manual control of the signals is effected through the medium of a pair of selector contacts L and R, one or the other of which may be selectively closed to establish the left-hand or right-hand direction of tramo, and by a delivery relay D which may be momentarily energized, by manual control from a remote point, such as a dispatchers oflice, through the medium of a centralized trado control system. When relay D is operated, it controls a pair of stick relays, R21-IS and L2HS, in accordance with the position of a signal lever located in the dispatchers cnice. As illustrative of such control, the signal lever, identified by the legend Sig, is shown connected by dotted lines to contacts L and R, and it is to be understood that contact L or R may be closed by moving the signal lever to the left or right, respectively, from its normal position, as shown. In order to clear signal LA2 or LBZ to permit the movement of traffic toward the left through the stretch, the operator at the dispatchers office Ywill by remote control close contact 'L and then momentarily energize relay D, thereby opening contact 35 in the stick circuits of relays RZHS and LZHS, and completing a pickup circuit from terminal B, contact L, contact 36 of relay D, relay L2H`S to terminal C, so that relay LZ1-IS will become energized. When relay D releases, the stick circuit of relay LZHS is closed from terminal B, back contact 35 of relay D, front contact 3l of relay ITR, back contact 38 of relay R21-IS, front contact 39 and winding of relay LZ1-IS to terminal C. When a train enters section IT, relay I'I'R releases and opens contact 3'! thereby releasing relay L2HS. Relay ITR is provided with a slow acting repeater relay ITZ which has a back contact 4B in multiple with contact 3l, which becomes closed when the stick circuit of LZHS has been opened for a time suicient to insure its release. It follows that relay D may be operated to pick up relay LZ1-IS even though section IT is occupied, and the stick circuit for LZHS will then be completed over the back contact lil of relay ITZ as is obvious from the drawings.

Relay LZHS controls a slow pick up slow release repeater relay LZHSP, and when relay L2HS becomes energized, if section 2T is uncccu pied, a circuit will be closed from terminal B, front contacts M and 42 of relays LZ1-IS and ETR, relay LZHSP to terminal C. Assuming that signal R2 is at stop, relay RZGP is energized over the circuit shown in Fig. ld, which may be traced from terminal B, back contact 43 of relay IIlHP and reverse polar Contact 44 of relay IDH in 5 multiple, back contacts 45 and 46 of signal relays RBiiland RAZH, relay RZGP, to terminal C. When relay I ZHSP is energized, a circuit shown in Fig. lc is closed from terminal B, front contact eil' of relay RZGP, back contact 48 of relay R2HS, iront contacts 49, 5B and 5I of relays ITR, LZHSP and LH, respectively, front neutral contact 52 and normal polar contact 53 of the switch indication relay IKR for switch I (closed only when switch l is closed and locked in its normal posil5 tion), relay LAZH to terminal C. When relays LAEH and LZH are energized, signal LA2 Will display a caution or a proceed indication, as Will be obvious from Fig, lf, which shows in detail the lighting circuits for signal LA2. If the switch is closed and locked reversed, relay IKR Will be energized in the reverse direction so that the righthand contact 53 will be closed and in that case signal relay LBH will be energized instead of relay LAEI-I to cause signal LB2 to indicate caution or proceed, as will be clear from Fig. lg.

The circuit for relay LH, as hereinbefore described, includes back contacts and 3| of the manually controlled relays LZ1-ISP and LZ1-IS, and I when relay MHS is picked up, this circuit is 30 opened at back contact 3i. However, when relay LHSP picks up, contact 3l is bridged by front contact 3S of relay LZ1-ISP so that the circuit for relay LZHWill again become closed. During the interval when relay LQHS is picked up and relay LZHSP is in the release position, if relay its is energized at the time, a circuit is closed from terminal B, back contact i4 of relay RAZH, wire I3, front contact i2 of track relay IGTR, relay iliZ, iront contact 2i' of relay EOS, front contact 28 of relay ISTR, Wire 29, back contact 3d of relay LZ1-ISP, front contact 3l of relay LZHS, resistor B3, back contact 2 of relay RAZH to terminai C. When ISBZ picks up, its back ContactV E8, shown in Fig. lb, opens the stick circuit of relay IGS, so that relay IGS will become released.

y Assuming that a train moving toward the right is approaching signal Iii, the operation of the apparatus of Figs. la` to lg, inclusive, is as follows: Since signal ii is governed by the section occupied by the train, it will be at stop, and relays I li-IP and I iS will be deenergized, so that relays LQH, LAZH and LBZH Will be deenergized. Therefore, relays LZGP, lH and IOHP may be energized so that signal Ifl will indicate caution or proceed, When the train passes signal I0, relays ESTR, IilH and IUHP will release consecutively, so that relay IBS will become energized, closing its iront contact 22 to complete the line G0 circuit including Wires B and I3 for the next signal in the rear of signal Ill to permit that signal to indicate caution, thereby maintaining the established direction of traffic as long as relay IGS remains energized. When the train passes out of the block section so that relay ITR picks up, relay till-I Will again become energized, and at the end of its time period relay IUHP will pick up and release IBS.

Assuming now that the operator at the dis- ?0 patcher@ one@ is provided with the usual os indication means for indicating the condition of the switch section IT, that the stretch is occupied by a train moving toward the right and approaching arm A of signal R2 at clear, and that an opposing train occupies the passing siding and is approaching signal LB2; as soon as the operator is informed that the train moving toward the right has entered section IT, he will operate his control apparatus to close contact L and to pick up relay D to cause stick relay LZ1-IS to become energized. Relay L2HS will pick up and Will be held energized over its stick circuit including back Contact 40 of relay ITZ as already described. Even though the rear portion of the train moving toward the right still occupies section 2T, the closing of front contact 3l of relay LEI-IS will cause relay lIlZ to pick up to release stick relay IGS. The release of relay IS opens the circuit for the next signal in the rear of signal I0 governing trafc moving toward the right to return this signal from the caution to the stop position. The signal relay for the latter signal, in turn, will open the circuit for the next signal in the rear of that signal in accordance with the usual tandem control of the signals employed in the absolute permissive blo-ck system, thereby cancelling the established direction of traffic and permitting the opposing signals for governing the movement of tramo toward the left up to and including signal II to be cleared. Relay II HP, released when the opposing traflic direction was established, will therefore now become energized, and since back contact 21 of relay IOS is noW closed, when the train moving toward the right passes out of se-ction 2T, and relay 2TRl picks up, relays L2HSP and LiH will become energized. As soon as the train passes out of section IT, switch I may be reversed by the operation of the remote control apparatus to effect the closing of the circuits shown in Figs. lo and lg for clearing signal LB2 just as soon as the switch completes its movement to its reverse position and the neutral contact 52 and righthand polar contact 53 of relay IKR becomes closed.

When the train moving toward the right passes out of section IT, the energization of relays 5SH and IIJHP and the consequent opening of back Contact 26 in the circuit of relay L2H is prevented because the circuit of relay EDH includes back contact 3 of relay LZHS, which relay is now energized.

Assuming now that relay IIlZ embodying my invention is omitted, and that the only Way to release relay IUS is by picking up relay IHP,

it Will be evident that the operator must delayv his energization of relay LZ1-IS to reverse the traffic direction until suiiicient time has elapsed after the train moving toward the right has passed out of section IT to permitrelays IGH and I ill-IP to pick up, in order to release IUS,'

and if relay LZHS is then picked up, a delay which in practice may amount to several seconds may occur before relay IGHP releases to deenergize the corresponding relay for the next signal in the rear, and the cumulative delay occurring before signal LBZ can be cleared may be prohibitive and such as to preclude the effecting of a meet Without stopping and delaying the opposing train approaching signal LB2.

By the practice of my invention, this delay is Wholly avoided, the cancellation of the established direction of traic is eifected While the stretch is still occupied so that the signal for the opposite direction may be cleared with a minimum delay as soon as the stretch becomes unoccupied.

Referring again to Fig. la, the circuits therein shown include in addition to those already described, a circuit including Wires 54 and I3 for controlling an approach relay R2AR which forms Ano part of my present invention but which is employed to indicate when a train is approaching the switch section IT.

Referring now to the modication of my invention shown 'in Figs. 2a. and 2b', the circuits of this form of my apparatus are generally similar to those of Figs. la to lg, inclusive, but it is to be understood that in this modified form Fig. 2a is to be substituted for Fig. 1ct and Fig. 2b for the corresponding portion of Fig. 1b. In this modied form of my apparatus, instead of using the circuit of the signal relay L2H comprising wires 29 and I3 for controlling the relay IIIZ, the circuit of the approach relay RZAR above referred to is employed to control a relay IGZ which is connected in this circuit in series with relay RZAR. The circuit for relays RZAR and IIIZ is from terminal B, front contact 23 of relay I IHP, front contact 55 of track relay I I TR, relay IUZ, front co-ntact 56 of track relay IQTR, wire 54, back contacts 51 and 58 of relays LZHSP and LHS, front Contact 59 of track relay ETR, resistor 5U, asymmetric unit SI, relay RZAR, asymmetric unit 62, front contact 33 of relay ZTR, common return wire I3, front contact I2 of relay IEITR, -front Contact 34 of relay IIHP, to terminal C. In the event a train moving toward the right approaches or passes signal I8, the circuit for relays RZAR and I QZ will be open due to the release of relay ISTR or I ITR so that back contact I6 of relay IGZ', included in the pickup and stick circuits of relay IGS as shown in Fig. 2b, will be closed. It follows, therefore, that relay IEIS may be energized in the usual manner. If, now, the operator picks up relay LZ1-IS when a. train moving toward the right enters section IT, as already described, relay IIHP being deenergized, a circuit for relay IUZ will be closed as soo-n as the train passes out oi section IT, which may be traced from terminal B, back contact S4 of relay lil-IP, front contact I2 of relay ISTR, wire I3, resistor Eid, front contact 58 of relay LZ1-IS, back contact 5l of relay LZ1-ISP, wire 54, front contact 55 of relay IITR, relay IGZ', front contact 55 of relay IITR, back Contact 23 of relay IIHP to terminal C, so that IilZ may be picked .up to release relay IilS under the same conditions and in the same manner as already described in connection with the similar relay IIIZ of Fig. la.

ln the arrangement shown in Fig. 2a., relay LEHSP is picked up when section 2T becomes unoccupied, as in the first form of my invention and will then close its front contact 5l and thus restore the circuit for energizing relay RZAR.

In the forms of my invention illustrated in Figs. 3 and 4, a saving of apparatus is effect-ed by the elimination of the repeater relay LZ1-ISP, and relay IIS is released by relay IIZ notmerely when traiiic is to be reversed, but when the existing tramo direction is to be maintained as well, and the circuits are arranged to employ wires 8 and I3 for the control of relay IUZ. To simplify the drawings, the circuits for relay RZAR have been omitted from these views.

The signal layout and the system of Fig. 3 are to be understood as being the same as that of Figs. la. to 1g, inclusive, except that Fig. 3 is to be substituted for Fig. 1a and for that portion of Fig. 1b showing the connections to wires 8 and I3' for controlling the ne-xt signal in the rear of signal IQ for th-e same direction, and it is also to be understood'that relay L2HSP is omitted and that a contact of relay LZ1-IS is to be substituted for contact 5I) in'Fig. lc.

Referring to 'Fig."3,' the circuit of relay IGH includes a back contact 65 of relay I 0S, so that xwhen a train moving toward the right passes signal I0, and relay IIS picks up, the circuit of relay IDI-I will be opened. Since the established direction of traflic in the portion of the stretch in the rear of the train is maintained as long as relay IIlS is energized, it follows that the circuits for the opposing signals will be held open and therefore relay IIHP will be deenergized. If now the operator wishes to reverse the traliic direction and picks up relay LZHS when the train enters section IT, as already described, a circuit for relay IIlZ will be closed as soon as the train passes out of section IUT, which may be traced from terminal B, back contact 34 of relay IIHP, contact I2 of relay IIiTR, wire I3,- front contact 3 of relay LZHS, wire 8, contact 9 of relay ISTR, front contact 65 of relay IS, relay IDZ, back contact 23 of relay IIHP to terminal C. Relay iZ will therefore pick up and open its back contact I Fig. lb, to release relay IUS, permitting a, prompt reversal of trailic as soon as the train passes out of the stretch, as hereinbefore described in connection with Fig. la. if, however, the operator wishes to maintain the existing traic direction from left to right and therefore does not pick up relay L2I-IS, a. circuit will be closed when the train passes out of the stretch and relay `ITR picks up, which may be traced from terminal B of the source adjacent signal II, back Contact 3d of relay IIHP, contact I2 of relay IUTR, wire I3, contact 33 of relay ZTR, back contact 2 of relay RAZI-I to terminal C of the source of current adjacent signal R2, through this source in series to its terminal B, back contacts I4 and I of relays RAZH and L2H, front contacts 5, 6 and 'I of relays LZGP, ITR and ETR, respectively, back Contact 3 of relay L2HS, wire 8, contact 9 of relay IilTR, front Contact 65 of relay IGS, relay IGZ, back contact 23 of relay I I HP to terminal C. It will be noted that the polarities of the two sources in the circuit just traced are additive, because the pole-changing relays IIHP and RAZH are both deenergized when the circuit for relay IIJZ is closed. Relay IZ will therefore pick up and release relay IIlS, and when relay IIJS closes its back contact 65, relay I @H will -become energized from the source adjacent signal R2 over a portion of the circuit just described, which does not include the source adjacent signal II. Since in this instance the existingtrac direction is to be maintained, it is desirable rto avoid a momentary opening of the caution control circuit for the signal in the rear of signal I0 includingwires 8 and i3', due to the opening of contact 22v of relay IBS before relay IBI-IP picks up to close its front contacts 20 and 2|. This is accomplished by bridging contact 22 of relay IGS by contacts 66 and 61 of relays IDZ and I BH, respectively, as shown in the drawings, and by making relay IIlZ a slow release relay, when necessary.

As will be clear from the drawings, the system of Fig. 4 is the same as that of Fig. 3, except for those changes rendered necessary by the staggered location of the intermediate signals II) and II. In Fig. 4, the source of energy adjacent signal II is not available at signal It, and 'hence the source adjacent the latter signal is employed to control relay IIIZ. Referring to Fig. 4, and assuming as before that the operator Ipicks up relay LZHS when atrain moving toward the right has entered section IT and that relay `IIlS-Iis picked up, a circuit for relay I DZ will be closed as soon as the train passes out of section I UT Which may be traced from terminal B, front contact 22 of relay IS, back contact 2| of relay IUI-IP, Wire I3', contact 66 of relay IITR, wire 67, contact I2 of relay IUTR, wire I3, front contact 3 of relay LZHS, Wire 8, contact 9 of relay IllTR, back contacts 61 and |58 of relays IIS and IIHP, Wire E9, contact I0 of relay IITR, front contact 65 of relay IES, relay IIlZ, Wire 8', back contact 2l) of relay IHP to terminal C. Relay IZ will therefore pick up and cause the release of relay IS, permitting a prompt reversal of tralic in the same manner as in the other forms of our invention hereinbefore described. In Fig. 4, when relay IIBS is picked up, if the existing trailic direction is to be maintained and relay LZ1-IS is deenergized, the connection from wire I3 to Wire 8 over front contact 3 of relay LZ1-IS in the circuit just described will be open, but a branch around front contact 3 in the circuit of relay IlZ Will be closed from Wire I3, contact 33 of relay Z'IR, back contact 2 of relay RAZH, terminal C of the source adjacent signal R2, through this source to its terminal B, back contacts It and @I of relays RAZI-I and L2H, iront contacts 5, B and 'I' of relays LZGP, ITR. and ZTR, respectively, back contact 3 of relay LZHS, to Wire 8, so that relay IGZ Will become energized to release the directional stick relay IIJS. In this instance also the I-I relay for the signal in the rear of signal Il) Which is energized over line Wires 8 and I3 from the source adjacent signal Iii, is maintained energized from the time relay SBZ picks up until relay IUI-IP picks up, by means of contacts 66 and B'I of relays IQZ and IH Which bridge contact 22 of relay IUS. It will be evident from the foregoing, therefore, that the operation of that form of my apparatus illustrated in Fig. 4 is the same as that of the apparatus of Fig. 3.

Although I have herein shown and described but a few forms of apparatus embodying my invention, it is understood that various changes and modications may be made therein Within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In a block signaling system for railroads, a signal at one end of a block section, a line relay governed by traffic conditions in said section for controlling said signal, a directional stick relay, means energizing the directional stick relay when a train governed by said signal enters the secsaid block section.

2. In a block signaling system for railroads, a signal at one end of a block section, a line relay governed by traffic conditions in said section for controlling said signal, a directional stick relay,

70 means for energizing the directional stick relay when a train governed by said signal enters the section at said one end, means controlled by the line relay for holding said relay energized as long as such train remains in the section, a manually controlled relay, means efective when said directional stick relay is energized to maintain the existing direction of traic in said block section, and means effective when said manually controlled relay is energized to release said direc tional stick relay and to establish the opposite direction of traic in said block section.

3. In a block signaling system for railroads, a block section, a line relay, means deenergizing the line relay when said block section is occupied, a repeater relay controlled by said line relay for governing the movement of traiiic in one direction into said block section, a manually controllable relay, a directional stick relay, a pickup circuit for said directional stick relay controlled by a front contact of said repeater relay and by traic conditions in said block section, a stick circuit for said directional stick relay controlled by back contacts of said repeater relay and of said manually controllable relay, and means effective when said directional stick relay is energized to maintain the existing direction of traic in said block section.

4. In a block signaling system for railroads, a block section, a line relay controlled by traffic conditions in said section, a slow acting repeater relay controlled by said line relay for governing the movement of traiiic in one direction into said block section, a directional stick relay, means energizing the directional stick relay when a train enters the section in said one direction, a stick circuit for holding said directional stick relay energized as long as the block section is occupied including a back contact of said repeater relay, a second line relay controlled by trailc conditions in said section and by a back contact of said directional stick relay for governing the movement of traiiic in the opposite direction into said block section, manually controlled means for selectively controlling said line relays, and means effective when said manually controlled means is operated to release said stick relay even though a portion of said block section is occupied, and to cause said second line relay to become energized as soon as said block section becomes unoccupied.

5. In a block signaling system for railroads, an intermediate signal for governing the movement of traffic in one direction into a block section, a line relay energized only when said block is unoccupied for controlling said signal. a directional stick relay for governing the movement of trailc approaching the block section in said one direction, means for energizing said directional stick relay when a train governed by said signal enters the block section, a stick circuit for said directional stick relay including a back contact closed when said line relay is deenergized, manually controlled means for preventing the energization of said line relay when the block section becomes unoccupied, and means controlled by said manually controlled means for opening said stick circuit to release said directional stick relay even though said line relay remains deenergized.

6. In a block signaling system for railroads, an intermediate signal for governing the movement of traiiic in one direction into a block section, a manually controlled signal for governing the movement of trame in the opposite direction into said block section, a line relay for each signal controlled by traiic conditions in said block section, manually controlled means for selectively controlling said line relays to permit the signal for but one traic direction to be cleared at a time, a directional stick relay so controlled as to become energized when a train governed by the intermediate signal enters the block section and effective when energized to prevent the clearing of .the opposingv signal, means for releasing said stick relay vprovided said manually controlled means is in condition to maintain the trail'ic direction existing when said stick relay became energized, and other means for releasing said stick relay effective when said manually controlled means is operated to reverse said trafic direction.

7. In a block signaling system for railroads, an intermediate signal for governing the movement oi traiiic in one direction into a block section, a line relay governed by traflic conditions in said block section and effective when energized to clearsaid signal, a directional stick relay so controlled as to become energized When a train governedA by said signal enters the block section, means controlled by said line relay for thereafter maintaining said directional stick relay energized as long as said line relay is deenergized, an opposing signal for governing the movement of traic in the opposite. direction through said block section, control means effective when operated to y clear said opposing signal provided the line relay and the directional stick relay are deenergized, said control means including means for maintaining the line relay deenergized irrespective of traic conditions in said block section, and means independent of the line relay for releasing the directional stick relay.

8. In a block signaling system for railroads, an intermediate. signal for governing the movement of traiiic in one direction into a block section, a head block signal for governing the movement of trafc in the opposite direction into said block section, a manually controlled selector for controlling the signals to select the direction of trac movement into the block section, a directional stick relay energized automatically when a train passes the intermediate signal to enter the block section and elective when energized to maintain the existing traiiic direction, means for maintaining said directional stick relay energized until the train leaves the block section, and means controlled by said selector for releasing said stick relay to cancel the existing traic direction `before said train leaves the block section.

9. In a block signaling system for railroads, an intermediate signal for governing the movement of traffic in one direction into a block section, a head block signal for governing the movement of traflic in the opposite direction into said block section, manually controlled means for selecting the traiiic direction, a directional stick relay energized automatically when a train passes theY intermediate signal to enter the block section and effective to maintain the existing tranic direction as longas said relay is energized, and means eiective before said train leaves the block section to release said relay provided the manually controlled means has been operated to reverse the trac direction.

10. In a block signaling system for railroads, a line relay'for governing the movement of trafc in one direction into a block section, an auxiliary relay, a directional stick relay for governing the movement of traffic approaching the block section in said one direction, a pickup circuit for said directional stick relay controlled by said line relay and closed vvhen a train moving in said one direction enters the block section, a stick circuit for saidv directional stick relay including a back con-- tact off said auxiliary relay and aback contact controlled by. said line relay, and an energizing;

circuit for said auxiliaryv relayincluding a front contact of, said directional stick relay.

11. In a block signaling system for railroads, a

line relay for governing the` movementI ofv traci in one direction into a block section, an auxiliary relay, a directional stick relay for governing the movement of tramo approaching the block section in said one direction'a pickupv circuit for said directional stick relayv controlled by said line,

energizing circuit before the train moves out ci' said section.

l2. In a block signaling system for railroads, a.

line relayffor governing the movement of traic in one direction-.into a block section, an auxiliary relay, a directional stick relay for governing the movement of traic approaching the block section in said one direction, a pickup circuit for said directional stick relay controlled` by said line relay and closed when a trainmoving in said one direction enters the block section, a stick circuit for said directional stick relay including a back contact of said auxiliary relay, a manually controlled relay for governing the movement or traic in the opposite direction into said block section, an energizing circuit for said line relayincluding a back Contact of'said manually controlled relay, and an energizing circuit for said auxiliary relay including front contacts ofsaiddirectional stick l relay and of said manually controlled relay.

13. In a block signaling system for railroads, a line relay for governing the movement of traic in on-e direction into a block sectioman auxiliary1 relay, a directional stick relay for governing the movement of tralic approaching the block section in said one direction, apickup circuit for said directional stick relay controlled by said line relay and'closed When a train moving in said onedirection enters the block section, a stick circuit for saiddirectional stick relay including a back contact of said auxiliary relay and a back contactV controlled by-said-'line relay, and meansvincluding=a line circuit closedyvhen said'blockY section becomes unoccupied' for energizing` said'auxiliary` relay.

14. In a block signalingsystem for railroads, aA

signal at onefend of ablock section, a line relay governed *by-1 trailic conditionsin saidsection for controlling said' signal, a directional stick relay, means Aforenergizing-the directional stick relay vvl'ienk a train governed by-said signal enters theV signals, a directional'stick relay, means energiz ing said relay When a train enters the block sec-v tion under thecontrolofA said one signal, slow acting means holding said relay energized as long as such train remains in the block section and for a predetermined time interval after it leaves the section, a manually controlled relay, means releasing the directional stick relay before such train leaves the block section if the manually controlled relay is energized, and means effective if the manually controlled relay is energized and the directional stick relay is deenergized for clearing the other signal in accordance with tramo conditions in said section.

16. In a block .signaling system for railroads, tvvo signals, one at each end of a block section for governing the movement of traffic into said section, means controlled in accordance with traffic conditions in said section for clearing one of said signals, a directional stick relay, means energizing said relay when a train moving in one direction enters the block section under the control o said one signal, slow-acting means holding said relay energized as long as such train remains in the block section and for a predetermined time interval after it leaves -the section, means controlled by the directional stick relay for maintaining the established direction or traflic as long as such relay is energized, a manually controlled relay, means effective when said manually controlled relay is energized for clearing the other signal in accordance with traic conditions in said section provided the directional stick relay is deenergized, and means controlled by said manually cont-rolled relay i'or deenergizing said directional stick relay while the block section is still occupied to eiiect the clearing of said other signal as soon as the stretch becomes unoccupied.

i7. In a block signaling system for railroads, a block section including two track sections, two signals, one at each end of said block section 40 for governing the movement of traine into said block section, means controlled in accordance with traine conditions for clearing one of said signals, a directional stick relay, means energizing said relay when a train enters the block section under the control of said one signal, slowacting means holding said relay energized as long as such train remains in the block section and for a predetermined time interval after it leaves the block section, a manually controlled relay, means releasing the directional stick relay if the manually controlled relay is energized and the train has vacated one of said track sections, and means effective if the manually controlled relay is energized and the directional stick relay is deenergized for clearing the other signal as soon as the train vacates the other track section.

l In a block signaling system for railroads, a block section including two track sections, two signals one at each end of said block section for governing the movement of traffic into said block section, a manually controlled relay, a line relay, means energizing the line relay only when the manually controlled relay is deenergized and both said track sections are unoccupied, a slowacting repeater relay controlled oy the line relay effective when energized to clear one of said signals, a directional stick relay, a pickup circuit for said directional stick relay including a front contact of said repeater relay and a contact closed when one of said track sections is occupied, a stick circuit for said directional stick relay including a back contact of said repeater relay, means effective if the manually controlled relay is energized and said repeater relay and directional stick relay are both deenergized for clearing the other signal in` accordance with traffic conditions in said block section, and means releasing the directional stick relay if the manually controlled relay is energized and said one track section is unoccupied.

HERBERT A. WALLACE. 

